Russian police arrested about two dozen protesters Sunday in Moscow, a week after more than 1,000 others were detained during a large-scale rally organized by a leading critic of President Vladimir Putin.

The Russian state news agency Tass reports that Sunday's arrests were made while protesters tried to conduct unauthorized marches toward the Kremlin from two public squares in Moscow.

Police had blocked off Pushkin Square, a traditional gathering place for demonstrators. Authorities also blocked access to several Internet websites the government said promoted "a planned illegal anti-government protest" in or near Moscow's Red Square.

It was unclear who organized the protests. A spokesman for prominent Kremlin critic Alexei Navalny denied that he was involved. He and hundreds of other anti-corruption demonstrators demanding the resignation of Prime Minister Dmitry Medvedev were detained last week.

Kremlin critic Alexei Navalny, who was arrested during March 26 anti-corruption rally, gestures during an appeal hearing at a court in Moscow on March 30, 2017.

Some critics of the Kremlin portray Putin as an overseer of a corrupt government that has awarded select friends and associates with vast sums of wealth.

The protests are occurring a year before a Russian presidential election in which Putin is expected to seek a fourth term. Navalny would like to run against the heavily-favored Putin, despite a questionable conviction on fraud charges that would technically disqualify him.

Last week's protests were the largest opposition rallies Russia has seen in several years.